Rewan Tremethick, currency analyst at TorFX, said: “GBP/EUR had a bumpy ride yesterday. Technical factors caused the pound to slump midday, although even without an unexpected drop GBP would have ended the day lower.

“Market jitters over Theresa May’s Friday speech remain, especially now rumours have surfaced Boris Johnson may quit the front bench if the negotiations don’t turn out the way he wants.

“GBP/EUR has now lost over a cent after hitting a two-month high on Friday.”

UK retail sales due out today could further influence the movement of the pound against the euro.